MongooseIM: Add basic integration endpoints.
This implements the basic integration endpoints for the mongooseIM XMPP server, see https://mongooseim.readthedocs.io/en/latest/authentication-backends/HTTP-authentication-module/.
To use it, set up a mongooseIM server for your domain, and set the http auth backend to active and add a http auth pool that points to your pleroma instance.
Snippets:
{http, global, auth, [{workers, 50}], [{server, "http://localhost:4000"}]}{auth_method, http}.This will then allow every local pleroma user to log in to your xmpp server.